`NewDataBuilder` allocated `make([]byte, 0, req.FileSize)` using the
client-supplied `int64` with no upper-bound check. The DRPC 4 MiB wire
cap limits message size but not the integer value, so a crafted message
with `FileSize = 1<<40` forces a 1 TiB allocation, triggering an
unrecoverable `runtime.throw` that kills the entire `coderd` process.
Add a `MaxFileSize` constant (100 MiB, matching `HTTPFileMaxBytes` in
`coderd/files.go`) and reject negative or oversized `FileSize`, plus
negative or excessive `Chunks`, before the allocation.
`BytesToDataUpload` also returns an error for oversized data to preserve
the encode/decode round-trip contract. Fix a pre-existing reversed
subtraction in the `Add()` overflow error message.
Closes https://linear.app/codercom/issue/PLAT-231
<details>
<summary>Implementation details</summary>
- `provisionersdk/proto/dataupload.go`: New exported `MaxFileSize`
constant; validation in `NewDataBuilder` and `BytesToDataUpload`. Fixed
reversed subtraction in `Add()` error.
- `provisionersdk/proto/dataupload_test.go`: New
`TestNewDataBuilderValidation` with 7 subtests.
- Updated all 5 callers of `BytesToDataUpload` for new error return.
- Audited all `make([]byte, ...)` in provisioner paths; no other
client-supplied sizes.
</details>
> Generated by Coder Agents on behalf of @f0ssel
# What this does
Dynamic parameters caches the `./terraform/modules` directory for parameter usage. What this PR does is send over this archive to the provisioner when building workspaces.
This allow terraform to skip downloading modules from their registries, a step that takes seconds.
<img width="1223" height="429" alt="Screenshot From 2025-12-29 12-57-52" src="https://github.com/user-attachments/assets/16066e0a-ac79-4296-819d-924f4b0418dc" />
# Wire protocol
The wire protocol reuses the same mechanism used to download the modules `provisoner -> coder`. It splits up large archives into multiple protobuf messages so larger archives can be sent under the message size limit.
# 🚨 Behavior Change (Breaking Change) 🚨
**Before this PR** modules were downloaded on every workspace build. This means unpinned modules always fetched the latest version
**After this PR** modules are cached at template import time, and their versions are effectively pinned for all subsequent workspace builds.
**This is just the protobuf changes for the PR https://github.com/coder/coder/pull/21398**
Moved `UploadFileRequest` from `provisionerd.proto` -> `provisioner.proto`.
Renamed to `FileUpload` because it is now bi-directional.
This **is backwards compatible**. I tested it to confirm the payloads are identical. Types were just renamed and moved around.
```golang
func TestTypeUpgrade(t *testing.T) {
t.Parallel()
x := &proto2.UploadFileRequest{
Type: &proto2.UploadFileRequest_ChunkPiece{
ChunkPiece: &proto.ChunkPiece{
Data: []byte("Hello World!"),
FullDataHash: []byte("Foobar"),
PieceIndex: 42,
},
},
}
data, err := protobuf.Marshal(x)
require.NoError(t, err)
// Exactly the same output
// EhgKDEhlbGxvIFdvcmxkIRIGRm9vYmFyGCo= on `main`
// EhgKDEhlbGxvIFdvcmxkIRIGRm9vYmFyGCo= on this branch
fmt.Println(base64.StdEncoding.EncodeToString(data))
}
```
# What this does
This allows provisioner daemons to download files from `coderd`'s `files` table. This is used to send over cached module files and prevent the need of downloading these modules on each workspace build.
This PR implements protobuf streaming to handle large module files by:
1. **Streaming large payloads**: When module files exceed the 4MB limit,
they're streamed in chunks using a new UploadFile RPC method
2. **Database storage**: Streamed files are stored in the database and
referenced by hash for deduplication
3. **Backward compatibility**: Small module files continue using the
existing direct payload method
Garrett Delfosse